diff options
Diffstat (limited to 'llvm/lib/Target')
| -rw-r--r-- | llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp index 41b58504daf..4e13fb8e202 100644 --- a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp +++ b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp @@ -899,12 +899,23 @@ bool AArch64InstructionSelector::selectCompareBranch( Register LHS = CCMI->getOperand(2).getReg(); Register RHS = CCMI->getOperand(3).getReg(); - if (!getConstantVRegVal(RHS, MRI)) + auto VRegAndVal = getConstantVRegValWithLookThrough(RHS, MRI); + if (!VRegAndVal) std::swap(RHS, LHS); - const auto RHSImm = getConstantVRegVal(RHS, MRI); - if (!RHSImm || *RHSImm != 0) - return false; + VRegAndVal = getConstantVRegValWithLookThrough(RHS, MRI); + if (!VRegAndVal || VRegAndVal->Value != 0) { + MachineIRBuilder MIB(I); + // If we can't select a CBZ then emit a cmp + Bcc. + if (!emitIntegerCompare(CCMI->getOperand(2), CCMI->getOperand(3), + CCMI->getOperand(1), MIB)) + return false; + const AArch64CC::CondCode CC = changeICMPPredToAArch64CC( + (CmpInst::Predicate)CCMI->getOperand(1).getPredicate()); + MIB.buildInstr(AArch64::Bcc, {}, {}).addImm(CC).addMBB(DestMBB); + I.eraseFromParent(); + return true; + } const RegisterBank &RB = *RBI.getRegBank(LHS, MRI, TRI); if (RB.getID() != AArch64::GPRRegBankID) |
